Earlier events :: 2014 :: STUDENT Poster

Why the range of the Sahara's large mammals is regressed?

Presented by
Abdullah Said
Al Azhar University In Cairo
Authors
Abdullah Said, José C. Brito

Introduction: What conservation problem or question does your study address?

No comprehensive analysis of the causes and patterns of biodiversity loss have taken place in Sahara to know why mammals range is declining. The aim to is model the distribution of 9 large mammals to quantify the regression rate and the set of environmental conditions where populations occur are needed to identify vulnerabilities. A quantification of the coverage of present protected areas of extant populations is needed to understand the current level of protection.

Methods: What were the main research methods you used?

A combination of presence only data from the field and literature are used to model the distribution of 9 mammals of the Sahara to answer the following questions:Have ecological-niche traits changed between past and present distribution?Which environmental factors are related with the distribution of species? Have they changed between the two time periods?How much have suitable areas been reduced between past and present distributions?What is the spatial coverage of protected areas with the present suitable areas?Ecological niche-based models (ENM) will be used to identify the most important environmental factors related to each species distribution and to identify suitable areas in the two time periods. Response curves from Maxent software will be used to visualise temporal changes in the profiles of relationships between species probability of occurrence and environmental gradients in the two time periods.

Results: What are your most important results?

Analysis is still underway but it is expected for Ammotragua lervia an increase of probability of occurrence in areas of high elevation and/or slope from the past to the present distribution. For Addax nasomaculatus it is expected a contraction in the range of environmental conditions occupied by these species from the past to the present distribution and most likely an increase in the relationship between species presence and small distance to the biome “Wildlands”.

Discussion: What are your important discussion points and what is the relevance of your results to conservation (if any)?

The work is still ongoing, just started the analysis. the work will give an insight into the conservation plans for the study species and analysis and prioritise the threats. in addition to conservation gap analysis and to plan the trans-boundary protected areas for migratory species.